There are many applications in the building industry where a portable, easy to assemble and disassemble frame assembly is desirable. Some examples are temporary floors, walls, and roofs, and the scaffolding systems employed to perform construction and maintenance tasks on various portions of buildings and other structures. Particularly in the scaffolding area, frame assemblies which have been employed in the past have typically been constructed so that the task involved could be performed on one portion of the building at a time. The constructed scaffolding frequently was not moveable from one portion of the building to another, but rather required disassembly before being moved and reassembly after being moved to another portion of the building. Furthermore, the scaffolding systems employed were constructed in such a manner that a considerable amount of time and energy were required to dismantle and then reassemble the platform each time it was moved. Other problems with prior art scaffolding systems were the safety risks involved in constructing and using the previous scaffolding systems, as well as the inability to change the level of most of these prior art work platforms without dismantling a substantial portion of the scaffolding.
Recently, a number of scaffolding system improvements have been made which are aimed at alleviating many of the problems noted above. U.S. Pat. No. 4,234,055, issued to G. L. Beeche on Nov. 18, 1980, describes a mobile suspension scaffold which requires assembly and dismantling only once for each construction site, at the beginning and the end of the job, respectively. The system described may be moved along the sides of a building and around building corners without being disassembled. A suspended scaffold system which may be used either independently or in conjunction with this mobile scaffold is the folding scaffold described in U.S. Pat. No. 4,253,548, issued to G. L. Beeche on Mar. 3, 1981. The system disclosed includes a plurality of work platforms which are foldably linked together.
Another problem that has been encountered in modern building construction and maintenance is the variety and complexity of the building shapes and structures being constructed. Designing and constructing customized scaffolding systems to fit particular building shapes and to accommodate particular tasks can be both time-consuming and relatively expensive. Contemporary scaffolding systems are required to be adaptable to a variety of configurations and applications. The constructed scaffolds must also have sufficient span strength and torsional rigidity to safely hold both the workers using the scaffolding and their materials.
These latter problems are addressed in co-pending U.S. application Ser. Nos. 861,133 and 048,108, filed May 8, 1986 and May 7, 1987, respectively, both filed in the name of G. L. Beeche, one of the inventors herein. The first of these two applications discloses a scaffolding system which employs modular components which may be combined to provide a variety of scaffold configurations and sizes. The latter application provides a scaffolding platform which may be used either independently of or in conjunction with the modular scaffolding system disclosed in application Ser. No. 861,133. The scaffold platform disclosed in application Ser. No. 048,108 is itself modular in nature, so that a variety of platform sizes and configurations may be provided.
The modular platform described in application Ser. No. 048,108 utilizes a truss frame component which is effectively braced in three dimensions. Such a configuration provides high resistance to structural deformation caused by externally applied loads, and allows an assembly of such truss frames to be employed as a truss beam for spanning long distances. The present invention provides a system of modular components which may be utilized to efficiently and economically form the type of truss frames and assemblies disclosed in application Ser. No. 048,108. In addition, the components of the system developed by the present inventors are uniquely designed to provide the truss frame assembly with a number of novel characteristics. Truss frame assemblies formed using the modular components of the present invention have application beyond the area of scaffolding systems. For example, lightweight structures having high span strength can be fabricated which are useful as concert staging, curtain walls, and floor and ceiling structures.
Accordingly, it is an object of the present invention to provide a modular truss frame system which is usable in a wide variety of applications.
It is a further object of the present invention to provide a modular truss frame system which utilizes a limited number of interchangeable components to form frame assemblies of various sizes and configurations.
It is another object of the present invention to provide a truss frame system for which assemblies of the truss frame components exhibit very high span strength and torsional rigidity, while at the same time being relatively light in weight.
It is also an object of the present invention to provide truss frame assemblies which can accommodate a variety of accessory attachments.